Auxiliary tool adapter for electric hand saws

ABSTRACT

A power tool attachment is provided which is adapted to be attached to a hand-held circular blade power saw, of the type commonly referred to as a &#39;&#39;&#39;&#39;skil-saw.&#39;&#39;&#39;&#39; The attachment comprises a base adapted to be clamped to the base of the saw, and a mandrel maintained in a position elevated above the saw base, having a rotatably mounted shaft and pulley affixed thereto. The shaft is driven by means of a flexible endless belt engaging the pulley and operated by a second pulley mounted on the motor shaft and engaged by the belt. Means are provided on the end of the shaft for attachment to various rotatable tools, or to a chuck which may be utilized in engaging the shafts of various types of rotary tools. In an alternative embodiment, an integral saw with its base portion including an arbor mounting means having a rotatable shaft is provided for accomplishing the same purposes.

United States Patent [191 Heisler [111 3,747,650 [451 July 24, 1973 [54]AUXILIARY TOOL ADAPTER FOR Primary Examiner-Donald R. scrim ELECTRICHAND SAWS Attorney-Roy A. Plant and Samuel Kurlandsky [76] Inventor:Clarence J. Heisler, R.R. No 2,

Springport, Mich. 49284 [571 4 ABSTRACT A power tool attachment isprovided which is adapted [22] 1971 to be attached to a hand-heldcircular blade power saw, 21 A 107,292 of the type commonly referred toas a skil-saw. The attachment comprises a base adapted to be clamped tor v a the base of the saw, and a mandrel maintained in a posi- [52] US.Cl. 144/1 E, 144/35 A tion elevated above the saw base having arotatably [51] Int. Cl. B27C 9/02 mounted shaft and pulley affixed]theretm The shaft is [58] Field of Search 143/43 43 32 R; driven bymeans of a flexible endless belt engaging the 144/35 35 1 1 E; 51/170170 PT; pulley and operated by a second pulley mounted on the I 408/20motor shaft and engaged by the belt. Means are pror r a v vided on theend of the shaft for attachment to various [561 a Retennces Citedrotatable tools, or to a chuck which may be utilized in UNITED STATESPATENTS engaging the shafts of various types of rotary tools. r2,544,810 3/1951 Strandberg' 144/1 E In an alternative embodiment anintegral saw with its g gg -g base portion including an arbor mountingmeans ry un i 3,583,106 6/1971 Dobbertin.... 143/43 A Z? armtatableshaft pmvldedfm accomphshmg 3,056,439 10/1962 4 Hall a a]. 144/35 A esame 8 Claims, 9 Drawing Figures i L 1 /0 u l l 4 /6 PAIENTED M41915 5'.747. 650

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INVENTOR CLARENCE HEISLER (Bantam ATTORNEYS PATENTEDJUL24|975 5.747. 650

' sum 3 er 3 INVENTOR CLARENCE HEISLER ATTORNEYS 1 AUXILIARY TOOLADAPTERFOR ELECTRIC HAND SAWS BACKGROUND OF THE INVENTION It has longbeen customary to provide various types of tool attachments to beoperated in conjunction with existing power tools in orderto. render thepower tools more versatile. The most common have been the variousattachmentsdesigned to be usedtogether with an electric drill. However,such applications have the disadvantages that ordinarily the motorsutilized for powering hand-operated drills are not exceptionallypowerful. Moreover, such drills do not normallyhave means for varyingthe speed of the attachment or means for holding and bracing theassembly in use. More recently, power tool attachments have beenprovided for use with chain saws since such saws generally have powerfulmotors. However, it is generally quite dangerous to operatesuchequipinent, since it is normally difficult to removethecuttingIteeth-bearing chain when it is desired to. operate the equipmentin conjunction with a power attachment.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide a power tool attachment designed tobe utili zed incombination witha hand-held portable circular power saw. I t

It is anadditional object to provide an attachment of thetype describedwhich may be readily attached to any type of hand-held circular powersaw having a base. I

It is still another object to provide a power saw attachment of thetypedescribed which may bemused to rotate tool attachments at variousspeeds.

It is still another object to'provide a power saw at, tachment which maybe readily adapted for use in carrying out a variety of functions undersafe conditions.

It is still another object to providean attachment for a power saw whichis relatively simple and inexpensive to build and to operate. It isstill'another object to provide a novel hand-held power-operatedcircular saw. having integral means provided upon which power toolattachments may be mounted.

' Still further objects and advantages of the invention will appearasthe description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, consists of the useful power tool attachment herein fullydescribed and particularly pointed out in the claims, the annexeddrawings, and the following description setting forth in detail certainillustrative embodiments of the invention, such disclosed embodimentsillustrating, however, but several of the various ways in which theprinciple of the invention may beused.

BRIEF DESCRIPTION OF THE DRAWINGS In the annexed drawings:

FlGLl is a top plan view of the power tool attachment of theinventionmounted on a hand-held poweroperated circularsaw.

FIG. 2 is a side elevational view of the apparatus shown in FIG. 1. a

FIG. 3 is a side elevational view of the power tool attachment shown byitself.

FIG. 4 is a top plan view of the. power tool attachment shown in FIG. 3.

FIG. 5 is a cross-sectional view takenat the line V--V of FIG. 4,looking in the direction of the arrows.

FIG. 6 is a cross-sectional view taken at the line VIVI of FIG. 4,looking in the direction of the arrows.

FIG. 7 is a side elevational view of the apparatus shown in FIG. 2,taken from the other side.

FIG. 8 is a side elevational view of another embodiment of the presentinvention, with a removable portion thereof shown in broken lines; and

FIG. 9 is an elevational view partly in cross-section, showing asub-assembly portion of the invention shown in FIG. 8.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS by engagement with a pin 15supported by a trunnion.

16. The motor is supported at the rear by a brace 17, FIG. 7, mounted onthe base 24. The brace 17 is provided with an arcuate slot l8 whichadjustably supports the motor 12 by means of a thumbscrewl9. A handle 20is affixed to the'motor. The saw. 11 also. has a conventionally providedfixed guard 21, FIGS. 1 and 2, and sting loaded pivoted guard 22, FIG.7.

The power tool attachment 10, as shown in greater detail in FIGS. 3-6,inclusive, comprises a base,25, FIG. 4, formed of a pair ofsubstantially parallel spacedapart rails, straps or bars 28 and 29having a cross brace 30 welded thereto, and a Ill-shaped handle 31 alsowelded to the rails 28 and 29. The spacebetween the rails serves as anadjustment slot for the attachment clamping assemblies and 42. The rails28 and 29 have at one end upturned mandrellsupports 33 and 34 having amandrel sleeve 35 welded to the ends thereof. Mounted in the mandrelsleeve 35, shown in greater detail in FIG. 5, area pair of bearings36and 37,- which may be sleeve bearings, roller bearings, ball bearings,or any other suitable type of bearings, and it is intended that theshowing be considered as diagrammatically illustrating same. A shaft 38is journaled in the bearings 36 and 37 and is provided with a threadedend 39 which may engage a chuck 40, shown in FIGS. 1 and 2 or,alternatively, which may directly engage a tool such as agrinding'wheelhaving a fitting with complementary threads integrallyprovided.

In order to affixthe power tool attachment to the saw base 24, clampassemblies 41 and 42, FIGS. 1 and 2, are provided comprising bolts 43and 44whose heads engage the rails 28 and 29 and having shafts extendingthrough the adjustment slotstherebetween. The bolts also extend throughapertures in arcuate clamp members 45 and 46 and are engagedby wing nuts47 and 48.-

Alternatively, steel washers may be used in place of the arcuate clampmembers 45 and 46, and it is intended saw, the nut which normally holdsthe saw blade is removed together with the saw blade. The pulley 23 isthen attached to the motor shaft 13. The attachment is placed over thebase 24 of the saw. As the attachment is brought toward the base 24, thepivoted guard 22 engages the rail 29 and is raised and maintained in theraised position. The adjustable clamps 41 and 42 are moved until theends of the arcuate clamp members extend over the forward and rear edgesof the base 24. The wing nuts 47 and 48 are then tightened sufficientlyto clamp the attachment to the saw base. The belt 26 is then engagedover the pulley 23 and the pulley 27. The thumbscrew 19 may be loosenedand adjusted in the arcuate slot until the belt is properly tightened.Any suitable tool may be mounted in the chuck 40, FIGS. 1 and 2, oralternatively, directly on the end of the threaded shaft 39. The entireassembly may be grasped by the saw handle and the U-shaped handle 31 andused. for any of a large number of operations such as drilling, sanding,grinding, buffing, et cetera. Additionally, by the use of a suitablecoupling attachment the apparatus may be used to start lawn mowerengines.

Because the motors conventionally utilized in handoperated circularpower saws are quite powerful, the apparatus is adaptable for use whereordinary electric drills would not be suitable. Moreover, because aflexible belt connects the motor to the shaft which operates theattachment tools, an element of safety is provided, since the beltpermits the pulleys to slide if too great or too sudden a load isapplied. Moreover, the speed of the mandrel shaft 38 may be changed bychanging the relative sizes of the pulleys 23 and 27. For example, witha small pulley utilized for the pulley 23, the use of the pulley havinga diameter of five inches for the pulley 27 will provide about 1700revolutions per minute. The use of a 7-inch diameter pulley will resultin a speed of about 1000 r.p.m. Still other speeds may be obtained bythe judicious selection of various size pulleys.

The attachment of the present invention greatly increases theversatility of the common hand-supported power circular saw. It permitsa large number of attachments to be utilized, provides a great deal ofpower to drive various attachments, permits the speed of the shaftdriving the attachments to be changed to suit the particular use, andpermits rapid change from one type of tool to another. Additionally, theunit itself is extremely simple to mount on a conventional powercircular saw.

FIGS. 8 and 9 illustrate another embodiment of the invention in whichthe leg or bracket for supporting the mandrel is manufactured as anintegral part of the base of the saw, either as an extension of thebase, or else, riveted or bolted thereto. As shown in the drawings, theintegral power saw and attachment unit comprises a power saw 51 having amotor 52, a shaft 53, and a pulley 54 mounted on the shaft 53. The motoris pivotally and adjustably mounted at the other end of the base 73 bymeans of an adjustable bracket 56 mounted at one end to the base andhaving a slot 57 provided therein. A bolt and wing nut combination 58clamps the motor in any desired position. The'arrangement is useful bothfor determining the depth of saw cut when a saw blade is mounted on themotor, and additionally for tightening a belt 72 utilized to drive thepower attachments. An arbor support 59 is provided as an integral partof the base 73 and is provided with a clamp 60 at its other endcomprising a fixed clamp jaw 61, an adjustable clamp jaw 62, and a boltand wing nut combination 6 for tightening the clamp. Mounted within theclamp is an arbor 64 comprising a mandrel sleeve 65, bearings 66 and 67,and a shaft 68 journaled in the bearings. A pulley 69 is affixed to theshaft 68 for driving the shaft. The end of the shaft 68 is provided witha threaded end 70 having a chuck- 71 mounted thereon. The belt 72 isadapted to be en gaged over the pulleys 54 and 69.

The apparatus thus shown in FIGS. 8 and 9 may b utilized insubstantially the same ways as that previously shown and described. Itis contemplated that the entire unit would be manufactured by theoriginal equipment manufacturer, and could be sold at a price less thanthe combined price of the saw and separate attachment (described inFIGS. 1-6).

While but two forms of the invention have been shown and described,other forms within the spirit and scope of the invention will now beapparent to those skilled in the art. Therefore, the embodiments shownin the drawings are to be considered as merely setting forth theinvention for illustrative purposes and are not intended to limit thescope of the invention herein described and shown.

Other modes of applying the principle of my invention may be employed,instead of those explained, change being made as regards the apparatusherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed. I thereforeparticularly point as my invention:

1. An apparatus adapted to be utilized for oprating power attachmentscomprising in combination:

a. an assembly from a hand-held electric poweroperated circular sawcomprising 1. a base, 2. a motor adjustably mounted on said base havinga rotatable shaft, 3. a pulley mounted on said shaft, and 4. a handlemounted on said saw; and b. power tool attaching means comprising 1. abase having upwardly offset mandrel supporting means, 2. a mandrelmounted on said mandrel supporting means having a shaft rotatablyjournaled therein, 3. a pulley mounted on said shaft, 4. means on saidshaft for securing tool attachments thereto, 5. means securing the baseof said assembly to the base of said power tool, and 6. a flexibleendless belt operatively mounted on said pulleys. 2. A power toolattachment adapted to be mounted out and distinctly claim on as assemblytaken from a hand-held electrical powg. means at the end of said shaftfor mounting tool attachments, the shaft of said mandrel being adaptedto be driven by a pulley mounted on the shaft of said motor andoperatively connected to the pulley mounted on said mandrel shaft bymeans of a flexible endless belt.

3. A power tool attachment according to claim 2, wherein said mandrelcomprises atubular housing having a bearing mounted at each end withsaid mandrel shaft journaled therein.

4. A power tool' attachment according to claim 2, wherein said clampingmeans (b) comprises an arcuate clamp member, a bolt engaged in anadjustment slot provided in said attachment base (a), said boltextending through an aperture provided in said arucate clamp member, anda nut engaging the threads at the end of said bolt for tightening saidclamp member in place.

5. A power tool attachment according to claim 2,

mounted at the end of said mandrel shaft to clear a sur-- face uponwhich said saw and attachment may be placed.

8. A power tool attachment according to claim 2, wherein said base (a)comprises a pair of metal bars maintained in substantially parallelspaced-apart position, the space intermediate said bars serving as aslot adjustably engaged by said clamping means (b).

1. An apparatus adapted to be utilized for oprating power attachmentscomprising in combination: a. an assembly from a hand-held electricpower-operated circular saw comprising
 1. a base,
 2. a motor adjustablymounted on said base having a rotatable shaft,
 3. a pulley mounted onsaid shaft, and
 4. a handle mounted on said saw; and b. power toolattaching means comprising
 1. a base having upwardly offset mandrelsupporting means,
 2. a mandrel mounted on said mandrel supporting meanshaving a shaft rotatably journaled therein,
 3. a pulley mounted on saidshaft,
 4. means on said shaft for securing tool attachments thereto, 5.means securing the base of said assembly to the base of said power tool,and
 6. a flexible endless belt operatively mounted on said pulleys.
 2. amotor adjustably mounted on said base having a rotatable shaft,
 2. amandrel mounted on said mandrel supporting means having a shaftrotatably journaled therein,
 2. A power tool attachment adapted to bemounted on as assembly taken from a hand-held electrical power-operatedcircular saw, said assembly comprising a base, a motor adjustablymounted on said base, and a handle, said attachment comprising: a. abase having upwardly offset mandrel supporting means, b. clamping meansfor mounting said base on the base of said saw, c. mandrel supportingmeans mounted on said base, d. a mandrel mounted on said mandrelsupporting means, e. a shaft rotatably journaled within said mandrel, f.a pulley mounted on said shaft, g. means at the end of said shaft formounting tool attachments, the shaft of said mandrel being adapted to bedriven by a pulley mounted on the shaft of said motor and operativelyconnected to the pulley mounted on said mandrel shaft by means of aflexible endless belt.
 3. A power tool attachment according to claim 2,wherein said mandrel comprises a tubular housing having a bearingmounted at each end with said mandrel shaft journaled therein.
 3. apulley mounted on said shaft,
 3. a pulley mounted on said shaft, and 4.a handle mounted on said saw; and b. power tool attaching meanscomprising
 4. means on said shaft for securing tool attachments thereto,4. A power tool attachment according to claim 2, wherein said clampingmeans (b) comprises an arcuate clamp member, a bolt engaged in anadjustment slot provided in said attachment base (a), said boltextending through an aperture provided in said arucate clamp member, anda nut engaging the threads at the end of said bolt for tightening saidclamp member in place.
 5. A power tool attachment according to claim 2,having a handle affixed to said power tool attachment base to facilitateholding and manipulation when in operation.
 5. means securing the baseof said assembly to the base of said power tool, and
 6. a flexibleendless belt operatively mounted on said pulleys.
 6. A power toolattachment according to claim 5, wherein said handle is in the form of aU-shaped rod.
 7. A power tool attachment according to claim 2, whereinsaid mandrel supporting means (c) is offset upwardly sufficiently topermit rotating tool attachments mounted at the end of said mandrelshaft to clear a surface upon which said saw and attachment may beplaced.
 8. A power tool attachment according to claim 2, wherein saidbase (a) comprises a pair of metal bars maintained in substantiallyparallel spaced-apart position, the space intermediate said bars servingas a slot adjustably engaged by said clamping means (b).